We plan to characterize revertants of VSV ts mutants in the G gene, and determine the nature of the mutated amino acid. We will attempt to determine whether secretory and membrane glycoproteins follow the same intracellular route in maturation from the rough endoplasmic reticulum to the Golgi and thence to the surface. Also we will determine whether all VSV strains, in a number of cell types, inhibit synthesis of cell proteins by the same mechanism.